Oceans have been warming nearly twice as fast since 2005 due to human-caused climate change, according to the Copernicus Marine Service report.

Accelerating Ocean Warming: A Clear Indicator of Global Climate Change

• Oceans, which cover 70% of the Earth’s surface, play a crucial role in regulating global climate.
• Continuous Rise in Ocean Temperature:
• • Ocean warming has been ongoing since the 1960s but has sharply increased since 2005.
  • The warming rate has nearly doubled, from 0.58 watts per m² to 1.05 watts per m² over the past two decades.
• Ocean Warming Reflects Global Warming:  Ocean warming is seen as a clear indicator of global warming.
  • It absorbs 90% of excess heat from the atmosphere caused by carbon dioxide and other greenhouse gases, as reported by the IPCC.

Enroll now for UPSC Online Course

About Ocean Warming

• The ocean absorbs extra heat from greenhouse gases, causing the water temperature to increase.
• Reasons for Ocean Warming
• • Greenhouse Gas Emissions: Burning fossil fuels, cutting trees, and industrial activities release gases like carbon dioxide (CO2) and methane (CH4) that trap heat, making the atmosphere and oceans warmer.
  • CO2 Absorption: The ocean absorbs excess CO2 from human activities. While this helps reduce climate change, it also causes ocean warming.
  • Solar Radiation: Changes in solar energy can also increase ocean temperatures over long periods, but it’s a small factor compared to human activities.
• Rising sea surface temperatures: Implications:
  • Marine biodiversity loss
  • Weak reef ecosystem
  • Disruption of food web
  • Disruption of ocean currents

Key Findings of the Report 

• Status of warming of oceans 
  • Marine Heatwaves: In 2023, 20% of the world’s oceans experienced severe marine heatwaves, affecting marine life and ecosystems.
  • Longer Marine Heatwaves:  The average duration of marine heatwaves has doubled since 2008, from 20 days to 40 days annually.
  • Permanent Heatwave in the Arctic:  Parts of the Arctic, particularly the north-east Barents Sea, have entered a state of permanent marine heatwave.
• Impact of Ocean warming (CMS report)
  • Severe Weather Events:  Warmer oceans fuel storms, hurricanes, and extreme weather by influencing global weather patterns.
  • Mass migration: Marine heatwaves can cause mass migration and mortality of species, disrupting ecosystems and nutrient distribution.
  • Sea Ice Loss and Record Temperatures: 2023 saw the lowest sea ice levels on record in the polar regions.
    • In August 2022, the Balearic Islands recorded their warmest coastal waters in 40 years at 29.2°C.
  • Coral Bleaching: Warmer water causes corals to lose algae that they need to survive, leading to coral bleaching and making them more prone to diseases, which harms coral reefs.
  • Sea Level Rise: Warmer oceans cause water to expand and polar ice to melt, raising sea levels. This leads to coastal erosion and makes coastal areas more vulnerable.
  • Disruption of Marine Food Webs: Rising temperatures change the distribution of marine species, disrupting the food chain and impacting fisheries and communities that depend on them.
  • Increased Ocean Acidity: Ocean acidity has increased by 30% since 1985 due to climate change, primarily from burning fossil fuels.
    • This increasing acidity threatens marine species like corals, mussels, and oysters, affecting their ability to form skeletons and shells.
      • It damages fragile ecosystems, and disrupts the flow of nutrients in the ocean.

Check Out UPSC CSE Books From PW Store